Fabrication of LiCoO2 films for lithium rechargeable microbattery in an aqueous solution by electrochemical reflux method

LiCoO2 films were directly deposited on electron-conducting substrates using electrochemical reflux method in an aqueous solution under ambient atmosphere at a fixed temperature between 100 and 200 degreesC with a fixed current density between 0.1 and 1.0 mA cm(-2). The structural and compositional purities of the deposited LiCoO2 film were confirmed by elemental analyses, X-ray diffraction pattern analyses, and Raman spectroscopy. According to the Raman spectroscopy and the voltage versus capacity profiles for the deposited LiCoO2 film, it appears that the deposited film consists of layered LiCoO2 phase (space group R3m). Although the deposited LiCoO2 film was fabricated in a very economical and simple way, it exhibits an initial discharge capacity of 54.1 muAh/cm mum and the discharge capacity retention of 85.6% over 15 cycles. (C) 2004 Elsevier Ltd. All rights reserved.